


Skeleton Magic

by UndertaleTrashBin



Series: Gaster Family Tales [2]
Category: Undertale (Video Game)
Genre: Gen, Not a main character tho, OC kind of
Language: English
Status: Completed
Published: 2015-12-13
Updated: 2016-01-19
Packaged: 2018-05-06 11:02:41
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 12,733
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5414408
Author URL: https://archiveofourown.org/users/UndertaleTrashBin/pseuds/UndertaleTrashBin
Summary: <blockquote class="userstuff">
              <p>A theory/self indulgence of how powers developed with Sans(and Pap but mostly Sans ok), and how powers are scary and dangerous and affect young monsters' lives.<br/>There shouldn't be any terrible violence but some chapters later on might focus on some fighting scenarios.<br/>EDIT: Title change from Gaster Family Backstories to Skeleton Magic</p>
            </blockquote>





	1. Powers (Part 1)

**Notes for the Chapter:**

> This fic doesn’t go into as much depth on the formation of Sans and Papyrus and kinda assumes you read the part one. It's really not mandatory but kinda helps explain everyone's relationship.

Gaster was a very worried monster. He worried about a myriad of things, the core, his job, the king, his science associates, but most of all was his boys. Gaster trekked through the snow earlier than usual, having a doctor’s appointment to make with the elder of his boys. Both of his children had very unique personalities, and while Papyrus may have been more obvious about it, Sans was certainly not any less unique than the younger. The ten year old was very bright, taking an interest in much of what his father did, but was always so lazy. He slept through the night peacefully, even when he was a baby, and he still took lengthy naps after(and during) school.

Gaster’s steps hurried as he fell back into concern, _So lazy..._ he thought. _Could that be connected to the fact his powers hadn’t formed yet? Or perhaps his laziness is connected to the lack of powers... The boy was 9 for god’s sake, he should have formed them several years ago._ Even his younger brother had surpassed him at that point, Papyrus having formed his powers pretty early at the age of 5.

THAT was quite the memory. The poor kid took it as well as a five year old can, but it was easy to tell just how terrified he was,

_Gaster had woken up to several loud crashes followed by muffled crying coming from the boys' room. Instinct kicked in and he rushed out of his room. A vivid orange glow came from the room- and initially he thought Sans had finally developed his powers before he heard the cries that were far to high pitched to belong to the nine year old._

_“dad?!” He heard Sans call out as he flung the door open, the older brother sitting with Papyrus trying to comfort the sobbing child. His left eye was squeezed shut, but the right was forced open by the bright orange light. A few things were knocked over, here and there, but nothing had taken real damage. Gaster scooped Papyrus up into his arms, letting his own blue magic wash over and absorb some of the excess magic from the 5 year old. It didn’t take long until Papyrus was mumbling apologies and falling back to sleep. Sans had looked terrified, but was a little relieved when Papyrus seemed to have calmed down. The two let out a sigh of relief when Papyrus didn’t even stir by being laid on his bed._

Coming back from the memory only made Gaster question the situation further, The two were formed in identical ways, what was it taking him so long? The man sighed as he unlocked the house with an audible ‘click’, deciding to grab a cup of coffee or two before the boys came home from school. It didn’t take much longer than it took to finish a cup for the boys to come rushing in- well, one of the boys came rushing in, the other one sauntered at a leisurely pace.

“ ‘sup, pops? you’re home early.” Sans noticed him immediately, grinning lazily at him from the doorway, and Gaster smiled back, hoping his concern wasn’t too obvious.

“Dad’s here?” Papyrus poked his head into the kitchen, copying his brother’s grin before rushing in to give him a big ol’ Pap hug. Gaster patted his son’s arms, which were tightly around him, before signing to Sans.

{Yes, Sans,} He signed slowly, patiently, making sure the boys were paying attention. Sans was quite fluent in sign language, but Papyrus’s attention span kept him from catching on as well. {You’re visiting the lab for a check up, remember?} Sans’s grin drooped significantly at that, he was nearly frowning.

“aw come on, i should at least get out of school for that.” Sans set his head in his arms at the table, staring up at his father.

“Am I coming? I like Hotland!!” Papyrus looked excited, and Gaster nodded.

{Yeah, wouldn’t leave you here alone.} Pap’s expression lit up, and he ran upstairs to change into something more suiting of Hotland before Gaster looked at Sans, pausing in his tracks.

{Sans?}

“i’m ‘listening’, pops.” Sans stared, anticipating the sentence to come.

{Where’s your school uniform?} Gaster looked very unimpressed all of a sudden, and Sans paused, guilt creeping onto his face. Sans was wearing a pair of athletic shorts, a t-shirt, and his far oversized hoodie- definitely not the school uniform they had purchased a year or so ago.

“uhhhh... dunno.” Sans shrugged, looking uncomfortable. Papyrus came down, saving his brother from a lecture as he tugged the two out the door.

“Let’s go, lazy bones-s!!” The boy was overzealous, though Sans supposed it was easier to be excited when you weren’t the one getting the check up. Sans was never fond of the poking and prodding of check ups, especially when it had to do with magic stuff. Unfortunately, Sans had a feeling it was going to be one of those. He frowned at the thought, it always sucked going to the lab, and it wasn’t like he was sick! Usually when he got check ups he and Pap went at the same time; so this couldn’t have been a regular one. _Dad must think I’m sick or something._ He briefly considered telling his father he wasn’t sick, but decided against it. He could tell him during the check up.

It didn’t take long before they made it to hotland, Sans removed his jacket as they got off the ferry, while Gaster kept on his sweater and all. Gaster took one of each boy's hands as they walked into the lab. Several colleagues waved to him, Papyrus returned the waves and Gaster gave a genuine smile in return. Most of them were fairly used to the sight of his boys, so it didn’t cause much commotion.

Doctor Fran met them at the door to her lab. She smiled at them, though Sans thought he could see worry behind the gesture. Gaster had become part time lab partners with her, and was comfortable with her lab as they stepped in. She bustled about to clear off a space on the table for Sans to sit, kicking a stool over for him to step up on. {Oh, I’ll be right back.} Gaster led Papyrus to a playroom down the hall, and until he returned Sans was alone with the Doctor. He felt uneasy, not because of the woman in particular, but because of the eery room. It had several empty tanks in it, and lots of machines he didn’t know the purpose of.

“is...” Sans began, but the way the doctor snapped her head toward him made him more nervous, “is something wrong with me?” He asked, voice barely louder than a whisper. The doctor seemed to relax a bit, and patted his arm comfortingly.

“I don’t think so.” She smiled warmly, even if a bit ingenuinely, before getting back to work taking Sans’s vitals and such, the base work for a check up.

“good, because that would be a real di-sans-ter.” The doctor chuckled a bit for him, relieving some tension.

“I think di-Gaster, works better, kid.” Sans shrugged, feeling a bit better after the joke. Gaster also helped by giving him a pat on the head as he entered the room. He moved around the room as well, helping the doc prepare the series of machines Sans was well acquainted with. He shifted uncomfortably, the room silent with the exception of the whirrs of the machines, and kicked his legs idly.

Sans looked between his dad and the doctor expectantly, and the Doc finally turned to Gaster. “What do you want to test first?” She asked, crossing her arms across her chest as she fully faced Gaster. “His magical form seems to be intact, no wavering visible,” The Doc tapped her pen on Sans’s leg lightly for emphasis, “he is fully responsive, shows no sign of illness or magical disruption.” Sans felt his chest puff in pride at the analysis. Exactly! He wasn’t sick, there was no need for this check up. Gaster sighed and signed,

{He hasn’t developed his powers yet.} Sans frowned. It was true, everyone at school had already developed their powers and used them whenever they got the chance to. He even had to sit out of gym class most days, since they really had just been focusing on magic control. The doctor shrugged, sliding a machine over,

“Well, let’s start with his HP.” She had Sans sit very still, and he felt the slight tingle of blue magic wash over him. It resembled his father’s, but it seemed more dangerous knowing it wouldn’t be as forgiving. The doc’s eyebrows knit, and she murmured “That can’t be right...” under her breath. Sans felt the magic wash over him again. And again. The doctor huffed in annoyance,

“Must be broken.” She left the room only to return with another version of the machine, and ran the test over Sans again. “Gaster, come look at this.” Uh oh. That didn’t sound good. Sans looked up at the adults as they read the machine and muttered to each other. They seemed to agree on something suddenly, and the doctor began writing furiously. She turned to Sans,

“Now,” She frowned, “Hp can be trained, but usually by your age it’s naturally become higher than 1.” Sans looked worried,

“so something is wrong with me...?” He tried not to sound nervous. The doctor shook her head.

“I’m not sure...” She paused, glancing over him with a critical eye. “We need to run more tests.” She tossed the machine to an unprepared Gaster, who barely caught it in time. Sans frowned in disappointment, more tests meant more poking and prodding. The doc handed Sans a hospital gown, and gave him an apologetic smile.

“Sorry, kiddo.” With a turn of the heel and averted eyes, Sans slowly, and reluctantly, changed out of his comfy clothes. He tossed them to the side and slid back onto the table.

**______________________________________________________________________________________________**

The check up lasted several hours. There was a lot of waiting for results that had to be manually printed out. There was a lack of answers as well. Eventually, Sans just laid down on the partially cleared off table.

“ ‘m goin’ to sleep. keep testing or whatever...” Sans didn’t even give the two scientists time to respond before dozing off.

**______________________________________________________________________________________________**

When Sans woke up he knew something had happened. The room he was in was dark and he felt sore all over. Despite not being able to see where he was or what he laid on, it was comfortable, so he turned over to snuggle under the covers.

“Sans?” The voice made him shoot awake, sitting up abruptly to glance around the dark room. The headrush it gave him was nearly unbearable, and he groaned before putting his head in his hands. He felt the broad hand of his father rubbing against his back comfortingly. “Hey, hey... You’re alright.” The- bed?- sank beside his small form as Gaster sat beside him on it. Sans sighed and leaned against him near cautiously.

“what happened?” Sans muttered into the man’s chest, he didn’t get a response except for the constant and comforting hand on his back holding him closer. They sat like that for a long time before Gaster turned on a lamp and sat back. Head having cooled down from its dull ache, Sans looked up at the man’s face. “how long...?”

{A week.} Gaster signed with a sigh of relief and ran a hand over his face. He hadn’t slept nearly at all in the week, too worried for Sans to do so. He had been going back home at nights, Papyrus was worried enough as it was, not that situations like this were entirely uncommon.

“how’s Pap?”

{Fine, been asking about you.} Gaster smiled with an underlying mix of apology and guilt.

“am i going home today?”

{Just a few final tests to make sure you’re good to go.} Sans’s expression and shoulders fell. {Nothing too bad, I promise.}

**Notes for the Chapter:**

> Let me know if you want a theory based chapter on what happened here! Otherwise we'll just move on to powers developing and kinda ignore what happened to Sans.


	2. Powers (Part 2)

**Summary for the Chapter:**

> Anything I could put here would be spoilers tbh. More stuff about powers I guess? Or, basically, Sans is sick of being stuck in the lab.

**Notes for the Chapter:**

> So this will be the last chapter I call "Powers" but tbh this whole fic is going to be based around powers I think I might change the title??? Ye I probably will edit it to change the title lmao

Sans couldn’t describe how he felt as anything but exhaustion. He was a tired little guy, but he hadn’t been _this_ tired in his life. The tests weren’t invasive or annoying, they were pretty regular, vitals-taking things. In fact, he barely felt a thing, but it could have been due to the fact that he practically dozed off anytime someone wasn’t talking to him. After finishing up, he fell asleep almost immediately. Gaster carried from the cold lab table to the slightly better hospital bed, and sighed,  _At least he doesn’t seem to be in pain._

There weren’t any signs that Sans was unstable, and the preliminary results seemed good, but just to be safe, the doc suggested he stay at least the night. Gaster wasn’t happy with the decision, but he agreed that it was the best choice of action at that point in time. _Perhaps a visit from Papyrus will help._ Gaster knew Papyrus was eager for Sans to be home to play again, and he had to go pick up the boy from school anyway. He stood and kissed the sleeping Sans on his head before leaving to pick up Pap.

{I’ll be back in a bit, Doc.} Gaster smiled at the hard working monster before going to walk out. She had been very frazzled with the whole Sans situation, it had all clearly freaked her out. They all had been worried for him.

“See you, Gaster.” She gave him a half smile as he walked out.

Gaster took a long walk to the little monsters’ school, it gave him time to think. The school had a while before Papyrus was let out anyway. While the walk took a long while, there wasn’t much time he had to wait before his son came rushing out.

“DAD!” The boy pinpointed Gaster quickly, usually Sans and him walked home together, but Gaster had taken up the duty with Sans out of order in the lab.

{Hello, Papyrus!} He grinned at the boy, and picked Pap up as he ran towards him. {How was your day?} Gaster signed with a free hand.

“GOOD! We had pizza for lunch. It was greasy but after you wiped it off it was ok!” Papyrus rambled on about his day, content to talk while being carried before realizing he wasn’t being carried home. Gaster was fine carrying him, it wasn’t all that uncommon for Sans or Gaster to just pick the little one up(the babybones didn’t weigh much anyway). “Where are we going?” He had stopped his thought mid sentence to ask the question. Hotland was easy to recognize, if not by the red soil then by the heat.

{Sans woke up today, he wanted to see you.} Gaster smiled softly, and Papyrus’s entire face lit up at the mention of Sans.

“He asked to see me?” His voice was excited, but he barely paused before launching in, “Well of course he did, I am The Great Papyrus, after all.” Papyrus grinned, and Gaster knew he must be relieved for Sans, though.

{I don’t know if he’ll be awake when we get there, buddy.} No need to get Papyrus excited if he would have to be patient. Patience was not one of the five year old’s strong suits.

_______________________________________

 

When Sans woke up, he felt much better. Hungry, still a bit tired, but better. Slowly, he sat up, covers falling away from his chest in the process. There was a dull ache in his head, mainly the left side, and he glanced around the room.

“hey, doc?” He called out a bit meekly. Her head popped around the corner before walking around it to talk to him.

“Sans! It’s good to see you awake.” She smiled at him, “Oh! You must be hungry, let me see if I can find you something.”

“thanks.” He paused to watch her go to the mini fridge in the room, “where’d my dad go?”

“To pick up your brother, he said he’d be back.” She couldn’t see him, but he relaxed when he heard that.

“is pap coming too?” This time the doc could hear the eagerness in his voice.

“I believe so. Is Sea Tea ok?” She pulled out a juice box labeled Sea Tea. Sans nodded, anything sounded good then, and she handed it to him. There was an awkward silence that was only disrupted by the sound of slurping. Sans debated for a long moment before asking a tough question,

“what happened to me?” The doc froze, stuttering,

“Er, ... that’s... difficult, to answer.” She took a long pause, Sans waited patiently. “It was an experiment. But it’s ok now.” Sans was clearly not satisfied with the answer, but before he could press it further he heard Papyrus’s shouting down the hall.

“BROTHER!” The two had matching grins upon seeing each other and Sans opened his arms for an inevitable hug. Papyrus obliged energetically, launching himself at his brother, who was thankful he was on a bed. Gaster grinned at the scene and pulled up a chair next to the bed. Papyrus was still hugging his brother, as if letting go meant he would leave.

{How are you feeling?} Gaster planned to bring dinner for them in later, but was happy to see that he had downed some Sea Tea to hold him over until then. Sans shrugged,

“better.” He turned his attention to Papyrus, “how was school? er, all the days i was out.” This question launched Papyrus into a very detailed explanation, play by play of what all happened that week.

“And that’s how I made a new friend.” He announced proudly, sitting beside his brother with a puffed up chest.

“that’s cool, bro. sounds like you were busy.” There was a twinge of annoyance in his voice, not at Pap, of course, but at the fact that he wasn’t able to hear all of this as it came made him more frustrated with the doc and his dad. Still, he was trying not to hold it against them, even if they wouldn’t tell him what happened. Gaster looked up from going over the doc’s notes at this, it wasn’t like Sans to complain too much, it brought a feeling of guilt twisting in his gut.

{Hey, I was thinking about running out for dinner. What do you boys want?} Both boys were concentrated on his hands, Sans responded first simply because he was used to reading longer signed sentences.

“i could use some grillby’s.”

“Spaghetti!” Gaster stood, the answers were common, but that night he would pick up both.

{Be good for the doc, I’ll be back.} He pulled the boys into a quick hug before walking out.

_______________________________________

Sans went home the next day, he was eager to get out of there. While Papyrus was at school, Gaster came by to pick him up. He was dressed in the t-shirt and shorts he had come with, jacket over his arm.

“hey dad.” He grinned up at the man, and took his hand, any leftover annoyance had pretty much fallen away over night.

{Hey, ready to be home?}

“yeah, can we take a shortcut?” It was rare that Gaster let him take others on ‘shortcuts’, the man seemed cautious of what they really meant, but usually when it was just them he would allow it. Gaster nodded,

{Let’s wait until we get outside first.} They walked through the halls, scientists bustled about ignoring the two as they left. Just outside the lab, Sans gripped Gaster’s hand a bit harder, leading him down to where the ferry person usually was, and they appeared just beside their garage in Snowdin. No blast of magic, no blacking out, nothing that would imply they weren’t going to greet the ferry person, it was as if that was just the logical continuation of where they were. Gaster chuckled a bit, shaking his head.

{How do you do that?} Sans shrugged and walked up to the door, waiting patiently for Gaster to unlock and open it. Gaster obliged, lost in his thoughts. Before Sans could wander off to his room to occupy himself while his brother was at school, Gaster asked,

{Are you up to picking up your brother?} He asked, he didn’t mind picking Pap up, but he would need to know. Sans nodded,

“yeah, i’ll get him.” With that, he walked up to his room. Tomorrow he had to go back to school, but his teachers knew he was in the hospital. Gaster went to pour some coffee before getting to work in his makeshift home lab.

_It didn’t work..._ Gaster thought. Sans’s powers still hadn’t formed, he showed no signs of it, either. The man should have been getting to work on core improvements and studying the barrier, but he couldn’t help but go over the doc’s notes on what they had done. A lot was left out. He walked to the lab at the back of their house quickly, studying the notes over and over. Why wasn’t this working? He didn’t want to mess with the poor boy anymore, but at this point he was concerned his magic would never form, whether they tried induce it or not. Not that the methods they had used to try to induce it were typical, but it was still disconcerting. Clearly he had magic, he had to have it to just... be alive. For a long while Gaster went over their processes and theories before deciding to work on his main projects. A few hours passed before he heard the loud voice of Papyrus from inside the house. He decided to take a break, and walked in to find Papyrus chatting happily with Sans.

{Do you want a snack?} He asked, Sans nodded and Papyrus agreed heartily. He pulled out a dozen spider donuts, wrapped two in napkins and went to hand them to the boys and listen to their conversation as he ate one himself.

It wasn’t until that night that the products of their experiment bared fruit.

The night was normal enough, they had a spaghetti dinner and Sans eagerly went to sleep, having to practically force Papyrus to lay down so they could turn the lights in their room off, and even then he was awake reading comic books in bed with his eye lit up orange. Gaster gave out good night kisses before settling down himself. Sans had drifted off into sleep, the first night in his bed in a bit over week and he felt safe again. That is, until there was a sharp pain on the left side of his head. He took in a big gasp of air, hand shooting up to his head. It felt like some had split his skull and grabbed his eye, squeezing it. He let out a groan.

“Sans?” Came a voice, much softer than usual from the opposite side of the room. Pap was scared. Sans curled up under the covers, breathing heavily. Papyrus spoke again, “Sans?!” He hopped onto his feet to walk over to the bed. A steady stream of tears fell from his eye sockets, hand over the left one. Papyrus tried to pry his hands away. “Sans, you’re scaring me.” Between gasps, Sans responded.

“get... dad...” Blue fire shot from under his hands, lighting up the whole room. Papyrus was already padding away, shouting something Sans couldn’t understand through the pain. He removed his hands from his skull, shakily trying to see through his eye. All he could see was blue. Waves of pain wracked through him again, and he felt himself being picked up. Gaster began trying to use his magic to disperse the excess coming from Sans, but he couldn’t keep up with the flow of magic. There was no sigh of relief from Sans, only a whimper.

“Papyrus.” Gaster spoke finally, turning to the boy. “We’re going to the lab, let’s hurry.” The boy frowned, not really sure what was going on but Sans let out a pained sound and he began running, Gaster on his heels. Pap opened the doors for them. Oddly enough, the ferry person was still available, and they caught a ride. They bid the family good luck as they ran to the lab. Papyrus was told to wait outside, to play in the play area. Gaster set Sans in a testing basin, the liquid having a continuous drain and refill, absorbing more magic than a monster could. The room was bathed in a dim blue light, resonating from Sans’s left eye socket. Gaster watched the machine’s process get slower and slower until everything seemed to have stabilized. Taking a deep breath, he pulled out his phone to call the doc. It was rare to get a call from Gaster, he rarely spoke as it was, so it absolutely was important if you get a call from him. She picked up,

“Hello?”

“I’m in the office, can you come in?” Gaster was suddenly tired.

“Gaster, it’s the middle of the night.” She heard a deep sigh on the other line,

“I know. It’s Sans.”

“I’ll be there.”

_______________________________________

Every time Sans seemed to have leveled out the magic flared up again. Gaster hadn’t slept in days, working and working. The doc was keeping a close eye on Sans, it wasn’t but a day or two later that Gaster came bursting in with tiny skull cradled in his hands.

“This is it.” He announced, rushing over to a bin of the expelled liquid that had absorbed the blue magic specific to Sans. He dipped the skull in it, color fading from the liquid and seeping into the tiny skull. The doc watched, and Gaster picked it up from the water. {We’re letting him out.}

“Gaster, he’s not stable..!” Gaster was already letting him out, the liquid draining around him magic began to form, glowing from his eye as he woke up. It was then that the tiny skull from earlier activated, glowing the same color of blue before circling around Sans in the air like a puppy. The adults watched with curiosity. Sans yawned, barely staying on his feet and the glow faded as he looked up at his dad.

“where am i?”  The skull responded to his voice, settling in front of his face and Sans gasped, afraid.

“He won’t hurt you.” Gaster pet the skull, still glowing blue. {You’re at the lab.} An annoyed groan came from Sans,

“again?” He reached out a hand for the skull to settle on the palm of his hand, and it did. Sans stared at it in awe, it was bigger than his hand but it rested nicely upon it, seemingly asleep.

{Go play with your brother.} Gaster said, and Sans did so, reluctantly, clearly confused. When Sans was out of earshot, the doc spoke,

“Gaster,” She spoke and he turned to address her, she grabbed his hand, “What happened?” There was a hole in the center of his palm.

**Notes for the Chapter:**

> Oh, in case you didn't catch on, the "tiny skull" is the first Gaster Blaster!


	3. Gaster Blaster Master

**Summary for the Chapter:**

> Maaaagic

**Notes for the Chapter:**

> This one's a bit short I guess :U I kinda ran out of inspiration part way through, but the next chapters are planned out and ready to go soooooo shouldn't be too long? Plus finals are finally over.  
> Also there will offically be 5 chapters in whole.

“What are you going to name it?!” Pap was absolutely in love with the, soon to be named, Gaster Blaster. It was like a dog, but it didn’t try to bite his bones! The thing may as well have been a pet to him. It was Saturday, and although he had a lot of homework to make up, Sans was hanging with Papyrus and doing nothing. He shrugged,

“we could name it after dad. he made it, after all.” The skull had grown quite a bit, now it was just smaller than Papyrus’s head, it laid in Sans’s lap, napping.

“Yeah, but that’s too confusing! We can’t have two Gasters.” Papyrus pet it, the surface smooth and pristine. Sans shrugged before laying out on the ground, startling the blaster in his lap a bit. Gaster walked in the front door then, glancing around the room before realizing the boys were on the floor. Sans and Papyrus looked up to watch him sign, before Sans realized he was watching the hands upside down and was unable to read it. Gaster stared at him expectantly and he sat up, smiling sheepishly,

“sorry, i wasn’t paying attention.” Annoyance flashed on Gaster’s face, and he resigned a condensed version,

{Training, let’s go.} When Sans stood, shoved on shoes and a jacket and looked ready to go, Gaster stopped him, {Bring the skull. Papyrus, we’ll be just in Waterfall, if you need us, call.}Papyrus deflated, he loved training, but he was pretty blatantly told he couldn’t go. Gaster blaster floating beside him, Sans and Gaster left.

“later, pap.” The walk to waterfall was quiet, and though he didn’t show it, Sans was nervous. He should be excited, everyone always talked about how great using magic is, but he couldn’t help but feel uneasy after everything that had happened in the last two weeks. The Gaster Blaster was responding to this, making circles around Sans and analyzing the environment. Eventually, Gaster stopped and turned to his son.

{Here is good.} He paused, deciding that it would be easier to explain out loud. “You know the basics, right?” Sans shrugged uncomfortably, technically they had gone over it in school, but since it didn’t apply to him at the time he didn’t pay attention. “I’ll just go over it again.” Gaster cleared his throat.

“Magic used in battles are attacks, but magic can extend outside of battle as well. Like fire magic to cook, or when I use my magic to catch things.” Gaster demonstrated, his purple tinted magic encompassing a ball he brought with them and lifting it off the ground. Sans followed it with his eyes as it spun around in the air. He held out his hands as Gaster set the ball down in them. “You try.” Sans focused on the ball, imagining it lifting up like Gaster had shown him, it didn’t move even an inch. Gaster frowned apologetically, taking the ball back and sitting on the soft navy colored soil. Sans sat in front of him.

“Sorry, I should teach you to activate your powers first.” Gaster’s eyes lit up purple, much like Sans had seen Papyrus light up his right eye orange many times before(he liked to show it off whenever he could).

“i don’t know how to do that...” He frowned, and Gaster’s eyes faded back to their typical color.

“It takes time to gain control over it like that.” Gaster paused, considering the blaster for a moment, _It shouldn’t inhibit the use of magic_ , he thought, considering the possibility of it more than completely taking it out of the question. “Think about how it felt when you got your powers.” That seemed to strike a chord with Sans, and he closed his eyes to concentrate. However, instead of just his own eye lighting up, the gaster blaster began charging as well to unleash a blast of the excess magic Sans had built up. Gaster noticed this, eyes widening as he moved out of the possible range of the blast. Only a faint glow was present in Sans’s eye, but when he opened it he was shocked by the release of energy from the previously small skull. Sans had jumped quite a bit at the blast, it wasn’t a quiet discharge of magic and he laughed nervously,

“holy sh- uhm.. crap.” Sans caught himself before cursing, and Gaster raised an unimpressed eyebrow at him. Sans’s eye still glowed despite the blaster not recharging for another blast. “is it supposed to do that?” Gaster shrugged half heartedly, it wasn’t what he intended it for.

{No, not really. Good job, though.} Gaster signed, smiling at the still faint glow in Sans’s eye socket. The glow was only growing stronger, but it wavered and flickered like fire.

“should i try the ball now?” Sans picked it up, twirling it in his hands. With a nod from Gaster, he focused in on it. As soon as a faint blue appeared around it, he got excited and broke concentration. “aw.” Gaster gave him an encouraging pat,

{Try again.} While Sans practiced, Gaster began studying the blaster. It had grown to a full grown monster sized skull, seemingly by the expulsion of magic. Since the blast, the skull’s eye sockets glowed, not in a blast-charging way, but as if it was reacting to Sans using magic. Sans groaned in frustration,

“it won’t move!” The ball sat innocently on the ground, covered in blue. Sans threw his hands up in frustration, and the ball smashed against the cave ceiling with a loud ‘pop’. The two stared up at it while it deflated like a whoopee cushion, speared by a stalactite.

{That was Papyrus’s ball.}

_______________________________________

“Have you decided on a name?” Papyrus’s voice came from across the dark room only slightly illuminated in orange, he was laying half off his bed, comic book raised above his face. Gaster had already read them their bedtime story, and they were supposed to be falling asleep. Sans opened an eye,

“i thought we decided on ‘gaster’?”

“Noooooo, it would too confusing.” Papyrus pouted, a thought occurring to Sans. He grinned,

“how about gaster blaster?” Papyrus had been told what all had happened during training by Sans, not that he was supposed to tell the younger. The flare of orange followed by a groan was Papyrus’s response. “unless you have a better idea?” Sans wasn’t opposed to a different one, but Gaster Blaster seemed the most suiting.

“Ugh. A temporary name.”

“why don’t you sleep on it, bro?” Sans yawned. Papyrus pouted, going back to his comic,

“I don’t want to.” Came his whine. Sans rolled over, already trying to get back to sleep. The Gaster Blaster was at the foot of his bed like a puppy, it was dormant.

_______________________________________

Sans laid back against the somewhat cleared off snowy roof a few weeks later. They were on break from school, even though it was about to start up again soon. He watched as Papyrus paced around Snowdin in search of him. They were playing hide and seek. The snow on the roof was think, and he sat up to watch the Gaster Blaster circle around him. It was nearly noon, almost time for training, and it was not his goal to get caught hiding on the roof. Sans searched his pockets, coming up with enough G for Grillby’s. It was when he stood that he slipped, panic flowing through him as his entire body shifted toward the edge of the roof. His magic lit up in response to the intense emotion, but without anything to aim it at it mostly went to the Gaster Blaster to alert it of its master’s danger. Just as he began falling, the Blaster zoomed underneath him, using the concentrated blue magic to bring him down softly.

However, the undignified screech he let out alerted both Papyrus and Gaster to his fall, both of which ran toward him as the Gaster Blaster saved his fragile 1 HP. Sans sniffled on the ground, the nine year old breathing hard as he tried to hold back frightened tears. Gaster rushed over, kneeling,

“Are you ok?” He spoke softly and scooped Sans up in his arms. The hesitant nod Sans gave was reassurance enough. Papyrus stood beside them, pouting to hide his relief,

“That’s why you’re not supposed to hide on the roof! Cheater.” Sans laughed softly, happy that Pap wasn’t acting scared for him,

“sorry bro.” The voice was neutral, but Gaster nodded in agreement with the younger brother,

{No more hiding on the roof.} He added it to the long list of rules for hide and seek. Gaster let Sans go, and they both stood back up. The Gaster Blaster bumped into Sans, nearly knocking him over in the affectionate bump.

“Wowie! It already looks like it’s grown!” Papyrus patted the blaster, it had clearly grown, the skull almost the size of the five year old. Gaster worried if it was a direct result of Sans’s overflowing power. _He might need another one._ He considered, looking down at his mismatched palms.

{Lunch?} The question was signed in hands, both boys nodded eagerly.

“can pap come and train with us today?” Sans had trained alone with Gaster for a while, and his powers weren’t stable enough for combat, but that didn’t mean Papyrus couldn’t even be present. Gaster paused while opening the door to their house, considering,

{Maybe. Let me think about it.} That was usually an indicator of ‘no’, but Papyrus appreciated Sans asking.

**Notes for the Chapter:**

> sorry if the ending was abruptttttt bluhhhhh


	4. Sparring with Papyrus!

**Summary for the Chapter:**

> Sparring! Cute Family times!

**Notes for the Chapter:**

> Sorry this is so late lmao. The holidays have not been kind to me.  
> These fics have been lacking in Papyrus a lot. For that I apologize. Maybe the next one in the series can be more focused on him! He’s a cutie.  
> This fic is unedited, let me know if you catch errors!

Papyrus was not the most aware of children. He knew he often wasn’t able to read the atmosphere in the room, but it seemed that things were... tense, lately. Sans had been learning to take control of his powers, which cut into his own training time, not that he minded, he just wished they could train together. Winter break, an odd name considering the lack of seasons in the underground, struck pretty quickly after the incident. It gave Sans times to catch up, not that he planned on doing so until the end of their break.

Pap was pretty used to rising before everyone else, Gaster took off quite a few days to watch the boys, but on off days he reminded Papyrus of Sans the way he slept in. The boy was patient, though, and he waited awake while coloring and planning puzzles for his family to come down. The tv droned on in the background, some human cartoon about speaking a language Pap didn’t recognize, but repeated dutifully under his breath when the on screen child prompted him to. His mind wandered from his puzzles, a little concerned about his dad and brother. A lot seemed to be going on that he didn’t fully understand, his dad had a hole in his hand, for pete’s sake! And as much as he loved the poorly named blaster that floated around and gave him the occasional ride, even he could see it had a weird attachment to Sans, past an owner/pet relationship. He pouted in annoyance, before sliding off the couch with a yawn.

It was about then that Gaster walked down the stairs, grinning at the sleepy looking boy,

{Tired?} He signed as Papyrus glanced up to him, his pout deepened,

“NO!” Papyrus marched to the kitchen to sit at the table to watch his dad pour a pot of coffee. While it drained into his mug of the day, he gathered up stuff to make a nice breakfast.

{I was thinking we could train today.} Gaster signed, grabbing his youngest’s attention. Papyrus lit up,

“Really?” He paused, “What will Sans do all day? We can’t let him sleep all day.” The boy frowned, leaning his head in his arms as he watched Gaster prepare breakfast. Gaster shrugged,

{He’ll live.} Papyrus looked skeptical, but didn’t respond other than with a shrug, causing Gaster to worry a bit. Papyrus wasn’t one to hold back what was on his mind. {Why do you ask?}

“I don’t know.” He frowned, “Why can’t we train together?” Gaster blinked, considering the possibility. Sans had been getting a lot better with his magic, and maybe if he told the gaster blaster to stay out of sparring... yeah, that could work.

{I... suppose we can, if you’re ok with waiting for him to get up.}

“WHO SAID ANYTHING ABOUT WAITING?!” Papyrus jumped up from the table, getting a few chuckles out of Gaster as the boy ran up to their room. He flung the door open, Sans not even flinching at the sound. Papyrus flung himself over the bed, and over his brother’s form, this time Sans did flinch, jerking awake but refusing to acknowledge that he was.

“Saaaaaans.” Papyrus rolled over, drawing a groan out of his older brother. It was a common event on school mornings, but the thought occurred to Sans that he had every right to sleep that particular morning.

“broooo, it’s breaaak.”

“But we’re going to train today!” Papyrus slid off the bed, standing back up to pester the half asleep boy more.

“together?” Sans opened an eye socket to peer over at the practically bouncing boy, Papyrus nodded. Letting out a big yawn, Sans sat up wearily. “is there breakfast?”

“Yeah!!! Dad’s making it now!” Papyrus was impressed at his ability to get his brother out of bed, it usually was much more of a battle, but he supposed a day spent with him was worth getting up early for! He watched his brother slide off the bed, and gasped sharply in realization.

“what? did i step on your foot? you know i weigh a skele-ton.” Sans grinned at Pap in amusement, but he didn’t even acknowledge the pun.

“Am I... TALLER THAN YOU?” Papyrus straightened up as much as he could, finding himself maybe an inch or two taller than the slightly slouching Sans. With a frown, Sans straightened up as well, without any added height.

“nah, there’s no way.” He left the room before Papyrus could officially compare, heading down to the kitchen.

“Brother! Wait!!” Papyrus rushed down after him, only to find his brother already sitting at the table patiently.

{Good job getting him up.} Gaster shot Papyrus a smile, it was a record amount of time getting him downstairs.

“Dad! I’m taller than Sans now!”

“no he isn’t.”

“YES I AM!” They paused, staring at each other before Papyrus turned to Gaster. “Let’s measure!!”

“...nah.” Sans said in opposition, but Gaster was already getting out the measuring stick.

“C’mon!!!” Papyrus worked on pushing Sans to get up while Gaster stood, ready with the measuring stick by the wall. They watched as Papyrus excitedly stood by the stick, standing as tall as he could manage without going onto his tiptoes. Gaster dutifully marked it with a pencil, and whistled,

{You’ve grown.} He turned with excitement, examining the marks with glee. Sans had barely changed in the last two times, but the marks were shorter than his newest. The older brother dragged his feet over, standing beside the stick dutifully as the mark was made. Papyrus practically screamed.

“I AM!” The grin that split the boy’s face was so smug and overjoyed that even Sans couldn’t help cracking a smile at it.

“i’m still the big bro though.” Sans’s voice was the closest to a pout Gaster had ever heard from him. They all sat down for breakfast, eggs still sizzling a bit as they were placed on plates in front of each skeleton.

_________________________________

 

Training was... difficult with two kids new to magic up against each other. There was a series of rules set out before the sparring between boys could begin, mostly reminding papyrus that Sans had 1 hp, but also that Gaster would be taking care of the blaster and it would not be used in the match. Both boys readied their magic, not having seen the other’s before, neither knew what to expect. Sans lazily readied a few bones, while Papyrus was ready to give it his all.

“Do you want to go first, Brother?” Sans shrugged at Pap’s question,

“nah, you go for it, bro.” 

*Sans readies a bone attack.

Papyrus tossed a few bones Sans’s way, a bit hesitant but only temporarily as he saw his brother was more than capable at dodging a few bones. His first attack ended with him feeling like he needed to ramp it up. Sans grinned lazily, jumping right into the battle,

*Papyrus is trying hard to play it cool.

Papyrus literally felt his heart, or soul, drop, weighed down by somewhat familiar blue magic.

“i see you’ve had a change of heart.” A surge of bones followed, Sans practically cackled at the groan that came from his brother. Papyrus dodged pretty flawlessly, Sans wasn’t throwing out anything too crazy.

*Sans readies a pun attack.

Papyrus started his turn off in a similar manner of the last turn, and just at the end he surrounded Sans’s soul in blue magic and brought it to the ground.

“You’re blue now, too!” Sans frowned in response, quite deeply, and Papyrus paused in fear he hurt him, “Are you okay?”

“yeah bro, i’m just so... blue.” He couldn’t keep up the frown and his grin cracked across his face again at his brother’s absurd expression. Gaster, who was looking on, raised an eyebrow at the boy.

“sANS! NO.”

*Papyrus is distracted by the bad joke Sans told and is frowning.

The bones seemed to come more frequently that turn and Papyrus hopped up just in time at the end of the attack when a row of bones popped up from the bottom of the screen, if only for a few seconds. Pap got hit once or twice that round, but each attack barely took even 1 hp, clearly no malice behind them.

“Wowie! That’s a cool trick.”

“aw, thanks bro.”

*The REAL battle begins.

Papyrus upped the speed of his attacks and introduced a series of bones that went from small to tall and back to small in the shape of a hill. Sans practically glowed with pride in his brother as he easily dodged everything thrown at him with plenty of time to spare.

“that was cool as heck, lil bro, it was like a tiny hill.” Sans made a motion with his fingers, imitating the shape of the bones.

*Papyrus whispers “ _ Nyeh heh heh _ !” 

Sans’s attack was very simple, along the same lines as the last one, before adding one really slow bone scroll across the playing field. Gaster burst out laughing to the side, and Papyrus stared at the bone in a mix of amusement and confusion, hopping over it easily.

“REALLY?” Sans just shrugged, a smug grin from their dad’s reaction on his face. Papyrus filed it away, he could do that, especially if it was  _ that _ funny!

*Sans is preparing something.

Papyrus’s attacks reflected his excitement by the response of the room. Bones came a bit more sporadically, fast and slow at odd times, but Sans didn’t really have an issue with it. He was a bit out of breath by the end of it, a drop of sweat or two appearing at his brow. Gaster kept a careful eye on him, but he seemed alright for now.

* Papyrus prepares a non-bone attack then spends a minute fixing his mistake.

Sans tossed out a few bones lazily, obviously growing a bit bored with attacking. Papyrus pouted,

“Don’t hold back, Brother!” His voice had a slight whine and Sans just shrugged, he wasn’t really one for attacking, but he liked to dodge.

*Sans prepares a bone attack.

Papyrus, more focused on cool attacks than dodging, threw a neat one at him. Not quite his special attack, but a cool one with bones on the ceiling and on the floor, more than one hill formation, and even a blue bone at the end. Gaster grinned at Pap and gave him a thumbs up, Sans had dodged flawlessly, but was clearly a bit winded, and their dad caught on quickly.

{Snack break!} Gaster paused the battle, handing each boy a Sea Tea and a Crab Apple from Gerson’s shop. Sans downed the Sea Tea in seconds, clearly thirsty, and sighed in relief. Papyrus laughed, sipping on his own after taking an hp restoring bite of the Crab Apple.

“Thirsty, Brother?”

“yeah, bro, your attacks make my throat bone-dry.” Sans chuckled in delight, and Papyrus groaned.

{That’s the third one since you started sparring.} Gaster signed with an eyeroll, both unable to hide their smiles.

“you guys love it.” Sans winked, and the group chatted idly as they snacked and Pap restored his hp.

When they returned to battling, their attacks escalated much more quickly, and before long Papyrus began warning Sans of his ‘special’ attack. After one of his hardest attacks yet, Sans grinned, sweating profusely and a little out of breath. It wasn’t that the moves were too difficult to dodge, it was the fact that the battle was becoming stamina based over skill, and everyone knows Papyrus has practically unlimited stamina.

“bring it on, bro.”

“Sans, it’s your turn next.”

“oh, right.”

*Papyrus readies his special attack.

Sans was using a steady stream of timing based jumps that got progressively faster. Papyrus was dodging pretty well, not having lost a lot of hp since their little snack break, despite being focused on attacks. His soul moved into the last bone, a blue, which knocked off a bit more health than the normal white bones. It wasn’t a worrying amount, so he kept going.

*Sans is starting to look really tired.

Papyrus took a stance, looking really serious, but nothing happened. Sans gave him a questioning look, as a tiny dog ran out from behind him, holding a series of bones in his jaw. Gaster began laughing again as Papyrus chased the dog around their sparring area in waterfall. Sans sat down behind his dad with a huff, leaning back against the sleeping gaster blaster.

{Tired?}

“yeah,” Breathing heavily, he admitted to being worn out, “just ‘cause i’m not losing hp doesn’t mean it isn’t tiring.” He shrugged, and Gaster smiled.

{It’s probably the best way to try and build it up anyway.} Gaster patted the boy’s head, Sans already falling asleep on the pup. By the time Papyrus came back with his arms full of bone attacks, Sans was napping peacefully on the floating gaster blaster.

**Notes for the Chapter:**

> Next chapter will be the finale, it is already partially written!
> 
> Hey, would anybody be interested in a drabble based fic? I would take requests mostly and have inconsistent word counts per chapter but I'd probably do ships as well.  
> Leave a comment to let me know!! Kudos are lovely as well<3


	5. It's not all Peaches and Plums

**Summary for the Chapter:**

> The finale of this fic, the start of another.  
> Sans has gotten his powers, but he begins to learn just what it will take to really get a solid grasp over them. After all, with great power comes great spidermen or something.

**Notes for the Chapter:**

> This is one of the longer chapters I’ve written and as a finale too! But never fear! The series is far from over, check out the rest of the “Gaster Family Tales” series, it’s ongoing.  
> Thank you to everyone who has spent the time to give me feedback, my writing can only go up from here!  
> The tags on this fic have been altered slightly, because of the introduction of Asgore.

Winter break ended too suddenly and far too soon. Sans walked with Papyrus to school, their mornings were a familiar routine that Sans enjoyed greatly. But, it definitely wasn’t the whole being awake in the early morning thing he liked, even if breakfast was good, usually just seeing how excited Papyrus was each and every morning rubbed off on him after a while. Sans let out a big yawn as he listened to Papyrus go on about everything that could happen that day.

“We have to get new desks when we get back too! I wonder who I will sit by?” Papyrus practically bounced to school, sometimes running ahead before pausing to wait for his brother to catch up.

“oh, i guess we will too.” Sans frowned, not really excited about that. He was a boy that enjoyed the comfort of routine. They arrived at the school pretty soon after that, having to split ways once reaching the campus. There were different entrances for the older and younger grades, and even though a year ago they’d had the same entrance, the grades were offset just enough for them to go to separate doors.

“have a good day, kiddo.” Sans grinned at his younger brother, and Papyrus proudly waved goodbye.

“I WILL! YOU TOO!” And with that, he ran off to wait by the doors for the school to open.

Sans rolled his shoulders as he made his way into his side of the building. It was going to be a long day. All of the grades were in one building, but kindergarten through 4th grade had one entrance, 5th through 8th had another, and 9th through 12th was the last entrance(besides the back ones for staff). Because of his height, Sans often jokingly got directed to the other doors, but he didn’t mind too much. No one really had a malevolent intent, he could take a joke.

The day passed without any incidents, Sans half slept through his first classes before the inevitable and least liked one came forward. P.E., physical education, was really just games that monsters his age could stretch their magical abilities to play. Today it was dodgeball. Sans had continued his training with Gaster(and occasionally Papyrus) outside of school, but now that he had developed his magic there was no reason to let him sit out of P.E. Teams were divided into team captains who chose from the tiny crowd of 5th graders. The captain of one team was an, oddly tall for his age, monster from Hotland, Sans didn’t really recognize him. The other was a too-big-for-his-britches kid from the Capital, one known for being a real jerk at times. There was only one school, so kids from all of the regions including the odd kid from the Ruins, Snowdin, Waterfall, Hotland, and the Capital, ended up in the same place.

Sans had a bit of a reputation in the school himself, that, just by pure laziness, he got to sit out of PE. Part of this could have been his own slight embarrassment in not having formed his powers and therefore not wanting to admit such an embarrassment to his peers, but it could have also been the slight gloating about getting out of P.E. Nonetheless, all the other kids were slightly annoyed, some more than others, that some tiny kid without working magic was being allowed to play. As the kids were divided into teams Sans found himself standing alone. The team captain he would be left to groaned in dismay upon realizing Sans was the only choice left. Ignoring Sans, the kid spoke to the lanky team captain on the other side of the gym,

“Hey, if you’ll take him,” the boy punctuated the word with a harsh finger pointed at Sans, “I’ll give you another kid too.” The other captain considered the deal, and with a shrug, agreed. Sans walked over to the team,l with embarrassment and hurt glowing on his face. It wasn’t enough to make him cry or anything, but it was upsetting.

Everyone got into position, Sans stuck to the back of the group, to just lazily dodge. The balls were carefully placed in the middle, dividing the gym in half before the game was signaled to start with the blow of a whistle. Magic flew through the air as children from both sides threw, at times hp reducing, balls at the other side. Most were pretty good at dodging, and although Sans was, he was in a sour mood after the way he was placed on a team. He didn’t really feel like retaliating as the game went on, simply dodging the odd ball that found its way toward him.

It wasn’t long before Sans was the last kid on his side, facing a group of four armed with most of the balls.

“Hey, baby bones!” The captain from the other side tried to grab his attention from the balls flying at him. Thankfully, he was a good multitasker and was able to both dodge and raise a non-existant eyebrow at the punk. Sans wasn’t the type of dodger that put a lot of jumping and leaping flare to his movements, most of the time it wasn’t hard to dodge anyway. He kept an eye on the kids, barely addressing the boy shouting at him.

“I’m talking to you!” The words were punctuated by a ‘boomerang’ ball, one where the user used magic to make it come back to their hand. Sans ducked and stepped to the side, dodging it easily, hands not even leaving his pockets. His team was starting to hesitantly cheer for him from the sidelines, watching him with interest.

“i know you are, i can hear, despite not having ears.” Sans spoke in the most monotone he could muster, he’d throw back after showing off his dodges. The boy would regret not choosing him and trying to barter him off on a rude assumption.

“Do you even have magic? You haven’t used any the whole game!” The boy called out childishly, making Sans pause long enough to nearly be hit. He looked around his side, there wasn’t a single ball for him to use, they had all bounced off the wall and rolled to the other side. When he looked back to the other side, each kid two each and were readied to throw them. Sans’s powers went alight as the balls flew toward him. Inches from his face, they stopped, each one surrounded in his blue magic. There was a moment of silence filled only with Sans chuckling a bit. All at once, he flung them back at the children, each one was enough to knock the kids over, but he really just sent the captain of team flying onto his butt. Sans shrugged as his team started cheering. Maybe his magic wasn’t such a bad thing.

 

_________________________________

 

Sans’s victory against the bully was short lived. It wasn’t long after that he was got well acquainted with him, morning, lunch, recess, and after school, and not in the good way. The boy was a furry monster from the Capital, and Sans concluded after the first time he tried to start a fight that he had some issues. He had done his best to deal with it somewhat smoothly, he knew he could talk to really anyone about it and get him taken care of, but the boy was really harmless. He didn’t even really have any ammo against Sans, they had only really met for the first time at that dodgeball game. That was what Sans thought at least, until he was at school one morning. Much like taking Pap to school, he learned the routine, not necessarily trying to avoid the harassment as he walked through the halls. His bully pinpointed him quicker than usual, bumping into him purposely and causing them to stop as Sans turned toward him.

“wow, rude.” The bully ignored the comment.

“I saw you walking home yesterday, baby bones.” Sans didn’t know if the boy even knew his name, it was always ‘baby bones’, as if it were a real insult. “Your brother is just like you, some weak little punk.” It was at that moment that he knew he had hit a nerve, for Sans sucked in a breath and had tensed up. The bully grinned, that was the most reaction he had gotten out of the boy.

“Oh yeah, he seemed a little more energetic than you. I wouldn’t have been surprised if he had ‘hopped, skipped, and jumped’ right off into the core.” The snot grinned, “Maybe he just needs a little, push.” He emphasized the word by giving Sans a hearty push, but it barely phased him. The words set in and Sans felt fear for his brother rise, he grabbed the kid and pushed him back roughly. His eye lights were gone from his eye sockets, emphasizing the seriousness of the situation.

“you leave my brother out of this.” The bully sneered,

“Or what?” And out of nowhere, the gaster blaster appeared, frightening both boys. The shot was pre charged, a sound similar to taking a deep breath was made by the blaster,

“wait!” Sans shouted, and, fearing he may actually injure the bully, he pushed the blaster off aim. It discharged a huge amount of magic in a ear blowing sound, and thankfully the hall was empty. It destroyed one side of the hallway’s wall, all windows down the hall, and the doors at the end of it that exited to the playground out back. Sans stared down the hall, numb with the shock of the blast and the fact that he hadn’t even summoned his magic. At least not intentionally... The bully was having a more extreme reaction, cowering in fear. Magic still permeated the air, the blaster innocently staring at its master. Sans ‘shortcutted’ it back home as quickly as he could, hands shaking.

“y-you... YOU FREAK!” The bully scrambled up and ran for his life, the moment the blaster disappeared. Sans stared down the hall in shock. A teacher stormed out from his room and into the hall. The teacher’s face betrayed his calm, though he tried to keep his voice level,

“What happened here?” He paused a moment, waiting patiently for the boy to respond. Sans tried desperately to keep from sobbing suddenly, his face flushed with embarrassment and shock.

“it.. was an accident...” His voice was small all of a sudden and the teacher took his arm, not completely gently but not painfully either, dragging him along. “where are we going?”

“To the principal’s office.”

“oh.” Sans paused, he’d never been in trouble before, “am i in trouble?”

“... Probably.” The teacher wasn’t pulling punches, Sans could certainly use some peace of mind. Thankfully, there weren’t a ton of people to see him get pulled into the quiet office, though he saw a number of people rush by them as they walked in. Other students drawn to the sound of the blaster explosion were stopped by a few fast acting teachers, janitors pushed through everyone to begin cleaning up the glass and rubble. Needless to say, school would probably be delayed if not cancelled.

The principal was already rushing about the office, occasionally talking on a walkie talkie about what happened. The teacher dragged Sans into the principal’s office and began searching through the phonebook. Sans sunk into his chair.

“are you going to call my dad?”

“I was going to call your mom if I could find her number, I know mom’s tend to be a bit more lenient.” The teacher smiled, trying to reassure Sans a bit.

“oh, uh, it’s just my dad.” Sans looked away awkwardly, and the teacher frowned,

“Oh.. I’m, I’m sorry.”

“it’s fine!” he spoke quickly, just wanting the conversation to end. The teacher eventually asked for his last name, and began dialing Gaster.

“Hello, is this Mr. Gaster?” Sans could barely hear a soft yes on the other side of the line,

“I’m here with your son, Sans. There’s been an... accident.” The teacher stared a bit pointedly at Sans, who tried to sink further into the seat. Sans heard Gaster yell on the other line, the teacher had to pull away from the phone, “Yes, yes he’s fine, no one is hurt. There is property damage, though.”

“No, you can’t talk to him yet he hasn’t talked to the principal- I mean, you should probably come in, yeah. Alright, see you soon.” Sans flipped up his hood, frown deepening. He knew he was in trouble if his dad was coming. The teacher and him sat in tense silence, Sans even began to doze off before the principal came in. She didn’t look angry... almost, impressed?

“Hello, you must be Sans. My name is Principal Darlene.” She took a seat behind her desk, and he nodded cautiously. He stared at the monster, she held an air of seriousness to her that demanded respect. “You were the one who destroyed the hallway, yes?”

“not on purpose.” He murmured, messing with his hands distractedly.

“What happened, then?” Darlene asked and the room went silent. Sans struggled with an answer, not wanting to lie but at the same time, he wasn’t a tattle tale. “It’s ok, we won’t be mad.”

“i lost control of my powers.” Sans decided. It wasn’t false, afterall. Darlene wasn’t taking that; Sans clearly wasn’t telling the whole story, the boy wasn’t even making eye contact. He sunk back into his hood.

“What caused this?” Her voice was level not growing impatient even if the teacher to the side’s stare was becoming so. Sans uneasily glanced to the side to look at the teacher, and the Principal caught the memo. “I’m sorry, Mr. Saddears, can you leave for a moment? I think Sans may be more comfortable one on one.” The teacher seemed alarmed by the sudden attention on him, but he nodded and left without a fuss. The principal turned back to Sans,

“Alright, so...” She let out a sigh, “was this really an accident?”

“yes!” Sans practically shouted, of course it was an accident, he wouldn’t have ever done something like that on purpose.

“Then, what caused it? You don’t just lose control of your powers.” She looked at him directly, but he still seemed unwilling. Despite his reluctance he spoke.

“there’s.. this kid. he makes fun of me,” Sans glanced up to make sure she was following, she was and gave him a quick nod, before he continued, “he threatened my bro.” Darlene took a sharp breath, nodding.

“I understand,” she frowned, “we could get him in trouble.” She offered, and Sans quickly shook his head. It was about then that Gaster opened the door to the office, a little out of breath. He placed a hand on Sans’s shoulder and stood behind him.

{Sorry I’m late. I am Gaster, nice to meet you.} Darlene shook his hand and smiled.

“It’s alright, I am Principal Darlene. I’ve just been talking to Sans here.” She stood, “Sans, would you wait outside so I can talk to your father?” She smiled warmly, but he could sense the unease behind the gesture. He walked out of the room and sat in a waiting chair just outside.

Gaster frowned as he watched his son walk out, {What happened?} he signed to the principal, who offered him a seat.

“Sans had an emotional upset and had a lapse of control in his powers.” She paused, Gaster actually relaxed in his seat, “However, I am uncomfortable allowing him at school when his powers are so easily compromised.”

{He just developed them over break.} Gaster frowned.

“I understand, but with the potential to... harm a monster so thoroughly, and with so little control, it just isn’t safe. We will look further into the cause of the emotional distress.” She frowned deeply, Gaster looked livid.

{How is my son supposed to learn?} he signed furiously.

“I can give you a list of tutors... Just get his powers under control, and he can come back.” The principal began shuffling through pamphlets, eventually handing Gaster one. He glared at it. “I really am sorry, sir. I must go over see the repairs, have a good day.” She stood, shook his hand again, and left.

Sans looked up to see the principal exit and sniffled, totally not crying. Darlene nodded to him, not even addressing the tears before rushing down the hall. The school bells rang, signaling that school was still to go on, despite the destruction. Gaster came out and put a comforting hand on Sans’s shoulder, leading him through the office and out the doors.

“it really was an accident...” Sans sounded stuffy under his hood, Gaster paused and took the hood down to look Sans in his, quite watery, eye sockets.

{I know. You’re not in trouble, we’ll figure it out.} Gaster wiped away a few of Sans’s tears and gave him a hug before leading them into the lab. He walked down the familiar corridors, the building far more empty than it once was due to rise in positions at the core. Sans shuffled his feet, trying not to fall behind his dad’s long stride. {Here.} Gaster stopped suddenly just outside his office in a little sitting room. {You can wait out here while I work. If you need me just pop in. Try not to bother any other scientists, be good.} Gaster leant down and kissed Sans on the head before entering his office.

_________________________________

 

Sans absentmindedly read a textbook that he would probably have to return to school when they realized he still had it. He glanced up when he saw motion, seeing a very large fuzzy monster before him. He seemed intimidating, large horns atop his head with, incredibly tall, and yet, something about him put Sans at ease.

Asgore stared at the small child in the waiting room, frowning gently. He seemed lonely,

“Aren’t you Gaster’s boy?” He spoke, voice slightly booming, but no real authority or bite behind it.

“yeah, why?” Sans felt a bit defensive, immediately regretting it when Asgore smiled apologetically.

“Shouldn’t you be at school?” He spoke softly, walking over to chat with Sans. Sans practically winced,

“i can’t.”

“Why not?” Asgore took a seat next to Sans, who launched into what happened. Afterall, the stranger seemed nice and it wasn’t like anything was going to happen. He gripped the sides of his textbook,

“so there’s this kid who likes to make fun of me, right?” Sans glanced up at the man, who seemed surprised by the shift in the conversation, but prompted him on anyway, “and then he said he would push my bro into the core, and i just... blew up. like, who threatens stuff like that? not cool.” He let out a huff of air, crossing his arms. Asgore frowned,

“I see. So what happened?” Sans froze,

“well, i don’t really have good control of my magic...” He looked guiltily at the ground, “no one got hurt, i pushed the blaster away at the last second but i hurt the school so now i can’t go back.” Sans rested his head in his hands and kicked his feet.

“You didn’t mean to, though, right?” Asgore asked, not exactly sure what the boy meant by ‘blaster’, a boy his age, size, and lack of control shouldn’t have such powerful magic.

“no! of course not! he may have been a jerk, but he didn’t deserve that.”

“So it’s fine.”

“yeah but i don’t have a way to learn things now.”

“Hmm,” Asgore thought about this, “Let me talk to your dad.” Sans blinked,

“you work with my dad?” he asked, surprised. He hadn’t put together why Asgore would know who his dad was or who Asgore even was yet.

“Well, he works  _ for _ me.” Asgore stood,

“but, my dad is the royal... scientist...” Sans stared as Asgore entered his father’s office.

_________________________________

 

Gaster didn’t even look up as the door to his office was opened,

“Sans, please go wait outside for a bit longer. Just a few more hours and we can head home.”

“I’m not Sans,” Asgore spoke matter of factly, grinning childishly as Gaster turned on him.

{Oh, I’m sorry your majesty. Sans had to be home from school today, so he’s in the office.} Gaster signed quickly, knowing Asgore hadn’t taken offense to the slip.

“I know, I already talked to him. He told me what happened.”

{Oh, really?} Gaster turned back to his work, deciding to multitask.

“He told me he can’t go to school anymore. Have you looked into finding a teacher?” Asgore smiled kindly, not trying to give away the fact that he was offering to take up a pupil. Gaster let out a sigh that sounded more like a groan, rubbing the bridge of his nose hole.

“No. He just got expelled today.”

“You know... I have a background in teaching...” Gaster glanced back at him, Asgore watched the gears turn in his head before the scientist spluttered,

“I couldn’t... I wouldn’t... I can’t push such a task on you! What would you even teach?” Gaster was flustered,

“Probably mostly magic, since the boy seems to be more along boss monster lines.” Gaster seemed to consider this for a moment, as if the thought process had never occurred to him before. “Besides, what do you think I really  _ do,  _ Gaster?” Asgore raised an eyebrow, and the scientist shrugged half heartedly, prompting him on. “Most days, I wait for humans to fall here. And there hasn’t been one since, well...” Everyone knew about the last human that had fallen, they only had two souls at the time, but the last one had nearly made it to Asgore before the royal guard had captured it. Gaster seemed resigned to the king’s logic,

“If it wouldn’t be too much trouble, Asgore.” He paused, “Please, don’t take him on if you aren’t ready for something like this...” Gaster wasn’t as concerned for Sans as he was for Asgore, the man was good around children but hadn’t really dealt with any kids since his own children had passed on. Asgore waved him off,

“When can he start?” The king’s excitement seeped into his voice.

“I’m going to help train his magic a bit, give him two days at least.” Gaster glanced back at his notes, they were the blueprints for the first Gaster Blaster, but perhaps he should modify them if he was considering the potential of Sans having boss monster capabilities.

“Alright, I’ll see you bright and early on Wednesday then.” Asgore winked at Gaster, only pausing momentarily. “Should I tell him, or do you want to?”

“Go for it, he apparently already trusts you anyway.” Gaster waved to him to go, turning back to his work.

Asgore walked out with a confident smile on his face and walked back over to Sans, who looked up at him. “I’m sorry, I don’t think I introduced myself-”

“you’re asgore dreemurr, the king.” Sans spoke before Asgore could finish, then quickly embarrassedly scratched at the back of his skull, “sorry, you just said you were my dad’s boss, and... anyway, i’m sans.” Sans held out his hand to shake, and Asgore grinned happily at him before taking it.

“You’re right, I am the king. It’s nice to meet you, Sans!” The shook hands heartily, “Now, I talked to your dad,” He sat down across from the boy, “And he said he would be ok with me becoming your mentor, to teach you stuff you’d learn at school. So how about it?” Sans looked shocked,

“what would i learn?”

“A couple different things, but we’d probably focus more on your magic.” Sans seemed to frown at that, Asgore caught on. “Not in a bad way, it’s just that, as a boss monster, I can help you understand control better.” Asgore took one of Sans’s hands gently, summoning a bit of magic in his other paw. Sans could feel it, glancing down at the seemingly empty paw with curiosity.

“When you have so much magic, it’s all trying to escape at once. While not all boss monsters are born with their boss monster magic. Unfortunately for us, we don’t get to grow into it.” He gave Sans a lopsided smile, and the boy’s grin widened up at him, curling the tiny skeleton hand in his paw. “Aaaanyway, I’ll see you Wednesday for you first lesson.” Asgore gave Sans’s hand back and stood up.

“yeah, see ya’.” Sans waved as Asgore left.

_________________________________

 

With few modifications, the newest member of the Gaster family entered the world. He let out a sharp grunt as he pierced through his ‘good’ hand, his magic intertwining with the piece of his magical form. He relaxed back in his chair to watch the skull form, it was nearly time to go take Sans home before picking up Papyrus, but he had to finish this up first.

Once it had taken a solid form, and Gaster had eaten a couple pastries he had grabbed for lunch to restore some hp, he called Sans in to observe the newly formed blaster. Sans walked in and looked up at it with caution, frightened by seeing another blaster appear without him meaning it to.

{Sans, look! I made a second... What is it you call them?}

“gaster blaster... why?”

“Well, the first blaster’s goal was to contain your excess magic, but since it has failed, I figured you could use another one!” The grin that covered Gaster’s face was so genuine that Sans couldn’t just act annoyed, so he held out a hand to the tiny new skull. It landed in the palm of his hand, nuzzling into it as if Sans was his mom. He cuddled the newborn as he listened to Gaster explain the logistics behind it,

“This one is calibrated to compensate for boss monster magic. I didn’t know why it didn’t occur to me before! Why else would you have so much magic? Clearly it wasn’t my own magic that caused it, so it makes me wonder what exactly prompted such strength. I wonder if Papyrus will also be a boss monster?” Gaster brightened up even further as he rambled on, and Sans groaned,

“does that mean you’re going to want to test my magic more?” Gaster tossed a rock to him, lighting Sans’s powers up to stop it in response. “i guess that’s a yes.” (Not long enough for you? Check out the continuation of this fic The King's Pupil http://archiveofourown.org/works/6174712/chapters/14147464 It picks almost exactly where this one leaves off, and will be more plot heavy. Thank you all so much for your feedback and appreciation! I love you all bunches have a good day.<3)

**Notes for the Chapter:**

> A drabble fic may also be on the way, focusing on cute childhood moments and ideas that I wanted to include but maybe didn’t quite fit the theme or something. There may be an alternative ending to this fic showing up in there ;)
> 
> AND AS USUAL- If you enjoyed this fic, check out the others in the series! If you enjoyed my writing, check out my blog at undertaletrashbin.tumblr.com, Kudos and Comments brighten my day- if you enjoyed it let me know! I always respond!

**Author's Note:**

> Check me out on my tumblr, undertaletrashbin.tumblr.com  
> Kudos and comments are lovely, I always respond!


End file.
